反应详情

Benzene (4 ml), ethylene glycol (0.12 g, 2.0 mmol) and p-toluenesulfonic acid monohydrate (0.01 g, 0.05 mmol) were added to 2-(2,5-dimethylphenoxymethyl)-α-methoxyiminophenylacetaldehyde (0.3 g, 1.0 mmol), and the mixture was subjected to azeotropic dehydration for 2 hours. After completion of the reaction, half-saturated brine (100 ml) was added, and the mixture was extracted with dichloromethane (50 ml) twice. The extracts were dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica gel chromatography (ethyl acetate/n-hexane) to give 2-(2,5-dimethylphenoxymethyl)phenyl 1,3-dioxolan-2-yl ketone O-methyloxime (0.30 g, yield 87.9%) as colorless crystals. mp 136-137° C.

1. additionwas added
2. extractionthe mixture was extracted with dichloromethane (50 ml) twice
3. dry with materialThe extracts were dried over anhydrous magnesium sulfate
4. concentrationconcentrated under reduced pressure
5. customThe residue was purified by silica gel chromatography (ethyl acetate/n-hexane)